A company or the like (hereafter referred to as a user) using an information system for business purposes may use an outsourcing service for information system-related business. The purpose is to supplement technical capabilities concerning the information system-related business, ensure the scalability, reduce costs, and avoid an investment risk. In many cases, the user concludes a service level agreement (SLA) with a service provider. The service level agreement defines the quality of services supplied from the service provider.
The service level agreement defines requirements for the quality of various types of services. The requirements include the response time of a transaction in an information system, minimum throughput of a communication line, and an upper bound for information system unavailability time. Accordingly, it is very important for an outsourcing service operation to monitor the actual service quality of the information processing system and verify whether or not a service level is satisfied. To monitor the actual service quality of the information processing system and analyze a problem, the service provider performs collecting of log data for a transaction process (hereinafter, referred to as “logging”), during a period to provide an outsourcing service.
Japanese Unexamined Patent Publication (Kokai) No. 2005-92885 discloses an example of such information processing system. The system embodied in Japanese Unexamined Patent Publication (Kokai) No. 2005-92885 records transaction data in the central logging database to determine a current service level. The system uses a service level parameter based on the prepared service level agreement between a customer and the service provider to determine whether or not the current service level violates the guaranteed service level. The system is implemented to specify a cause if the required service level is not satisfied.
As another related art, Japanese Unexamined Patent Publication (Kokai) No. 5-89051 discloses the following logging technology. The technology measures response information by initiating a transaction from a terminal connected to a host. The technology outputs a result to a log file on the terminal. When the log file exceeds a specified size, the technology transmits log file information to the host.
As yet another related art, Japanese Unexamined Patent Publication (Kokai) No. 2001-350640 discloses the following technology for monitoring transaction performance degradation. Transaction performance degradation monitoring means periodically collects transaction process situations to monitor the performance degradation. If the performance degradation is detected, a status flag is set to indicate the performance degradation.
The transaction process response time is especially important among service items supplied from the service provider. The IBM Tivoli Monitoring for Transaction Performance product (see, e.g., “IBM Tivoli Monitoring for Transaction Performance: Administrator's Guide”, written by International Business Machines Corporation, issued in September 2004) provides the function to monitor the transaction process response time.
The system described in Japanese Unexamined Patent Publication (Kokai) No. 2005-92885 similarly collects transaction data irrespectively of transaction processes. When many items are to be logged, the system needs to process a large amount of transaction data. A system load increases accordingly and output processes concentrate on a storage device. This may delay the transaction process. Generally, an outsourcing service is provided for a long term (e.g., several years), causing a large amount of transaction data to be recorded. On the other hand, there may be a case of logging only a few items to decrease the amount of transaction data to be recorded. However, it may be difficult to acquire sufficient information needed to record the actual service quality and to analyze a problem.
The transaction process system performs many transaction processes. A log is recorded for each of these transaction processes. The contents of the log may vary with the response time of each transaction process. Specifically, it is highly possible that a problem occurs when the transaction process causes a long response time. That transaction necessitates many pieces of information to be recorded for later analysis of the problem. Conversely, a problem is not likely to occur when the transaction process causes a short response time. That transaction may necessitate minimal information to be recorded for later analysis of the possible problem.